Hi,
From the trace of oracle it looks to me that you have used max utilization of process parameter.
Please use the below command to check the session and the processes.
select resource_name,current_utilization,max_utilization,limit_value from v$resource_limit where resource_name in ( 'sessions', 'processes');
So increase processes and sessions parameter and take database bounce to reflect changes.
Hope this helps .
Thanks
Rishi Abrol